Removable back for seats



A. P. DERBY. I REMOVABLE BACK FOR SEATS.

171116715507" alum .P .Derkby,

UNITED STATES.

" PATENT OFFICE.

ALVAN P. DERBY, or SOUTH WEYMOUTH; MA SACHUSETTS.

REMOVABLE BACK FOR SEATS.

SPECIFICATION forming partof Letters Patent NO. 518,097, dated April. 10, 1894.

Application filed October 24, 1893. Serial No. 488,982. (No model.)

To all whom it may concern: i

Be it known'that I, ALVAN P. DERBY, of South Weymouth, county of Norfolk, State of Massachusetts, haveiinvented an Improvement in Removable Backs for Seats, ofwhich the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention has for its object to provide a novel removable, preferably yielding, back seat'to which, the back is to be applied, one

of the said members carrying the back which is removable by releasing the clamping members. The back is preferably mounted upon one or more suitable springs which permit it to yield more or less to accommodate the po sition of the person occupying the seat, and the said back is preferably detachable from the clamping member which supports it.

In the drawings, Figure 1 represents in side elevation a seat shown as a piano stool equipped with a back embodying this invention; Fig. 2, a rear elevation of the back and its supporting members; and Fig. 3, an under side View of the supporting members.

Referring to the drawings, in the particular embodiment of myinvention there shown, A represents any usual seat or stool to which the back is to be applied.

In accordance with this invention I provide one or more sets or pairsof clamping members a, a, I having herein shown two such pairs, the members a having their front ends upturned as at a to engage the front of the seat, and at their rear ends provided with suitable ears a adapted to embrace the guiding surfaces or ribsa formed'at the under sides of the members a, the members a being thus adapted to slide on and with relation to the members a. The members a at their rear ends are provided with upwardly extended socketlugs a said members being also provided with depending lugs a through which are loosely passed the threaded adj usting or clamping rods 6, threaded in lugs ta on the under sides of the clamping members a, as shown, the said clamping rods at their side of the back D, the latter being retained in vertically adjusted position upon and with relation-to'the said spring rods by means ofone or more thumb screws d shown as tapped into the eyes 01. I

To apply the back, the'clamping rods or devices b are turned to separate the clamping members a and a, to sufficiently enable the clamping lugs or ends thereon to be passed up at the front and back-of the seat, when the said clamping devices are again rotated in an opposite direction to draw the said clamping members together, to cause the same to tightly clamp the seatframe and thereby remain rigidly secured thereto. The lower ends of the spring rods owhich during the clamping operation have preferably, together with the back D, been removed, are now inserted in the socket lugs a and the operation of applying the back to the Seat is complete.

If at any time one who occupies the seat does not wish to have the back in position, the latter may be removed by simply lifting the spring rods from the socket lugs a ,leaving the clamping members Still in position upon the seat to receive and again hold the back when the latter is desire 13y means'of the thumb screws d the back may be adjusted to fit the back of theperson occupying the seat.

AS herein shown and preferably when two or more pairs of clamping members are employed, the members a are connected by means of a cross piece a ,see Fig. 3.

While I have herein shown and prefer to 'employ at least two pairs of clamping members and back supporting springs, yet this invention is not restricted in this particular, for any number of pairs of clamping members and back supporting spring or springs may be employed and still come within the scope of this invention. Neither is this invention limited to the particular construction or shape of the parts herein shown, for it is evident the same may be varied without departing from the spirit and scope of the invention.

I claim 7 Ina removable seat back, two pairs of clamping members, the members of each pair having upwardly extended lugs to embrace a seat, guide-ways on one of the members of each pair in which the other member of each pair is free to move, means to move the members of each pair one with relation to the other to clamp and hold between them a seat I5 2. connection between one of the members of one pair and a corresponding member of the other pair, and a back carried by said clamping members, substantially as described.

In testimony whereof I have signed my 20 name to this specification in the presence of two subscribing witnesses.

ALVAN P. DERBY.

Witnesses:

FREDERICK L. EMERY, AUGUSTA E. DEAN. 

